Probably. But a really crushing Confederate victory that ended the war -- assuming such a thing was possible -- would really have encouraged secessionist forces and they'd try to secure as much territory as they could.
If the war just fizzled out with a stalemate and the election of McClellan people might just want to get back to life as usual, but some amazing -- improbable, impossible -- rebel triumph would really have gotten secessionist juices flowing.
That brings up the question of whether the Civil War would really have ended with a Confederate victory. The USA and CSA might have made peace, but with militias and partisans and guerrillas fighting in Kentucky and Missouri and Maryland (and in West Virginia and East Tennessee as well), wouldn't the two nations be drawn back into war?
There never should have been any killing, but when wealth is involved, the Plutocrats don't care about death.